Synthesis and properties of macroporous SiC ceramics synthesized by 3D printing and chemical vapor infiltration/deposition

Abstract

Open porosity cellular SiC-based ceramics have a great potential for energy conversion, e.g. as solar receivers. In spite of their tolerance to damage, structural applications at high temperature remain limited due to high production costs or inappropriate properties. The objective of this work was to investigate an original route for the manufacturing of porous SiC ceramics based on 3D printing and chemical vapor infiltration/deposition (CVI/CVD). After binder jetting 3D-printing, the green α-SiC porous structures were reinforced by CVI/CVD of SiC using CH3SiCl3/H2. The multiscale structure of the SiC porous specimens was carefully examined as well as the elemental and phase content at the microscale. The oxidation and thermal shock resistance of the porous SiC structures and model specimens were also studied, as well as the thermal and mechanical properties. The pure and dense CVI/CVD-SiC coating considerably improves the mechanical strength, oxidation resistance and thermal diffusivity of the material.

Computational thermodynamic study of SiC chemical vapor deposition from MTS‐H2*

“…The compositions of both gas and condensed phases at equilibrium are highly dependent on deposition conditions. The dominant molecular species carrying Si F I G U R E 9 Deposit purity as a function of temperature and pressure at the select H 2 / MTS ratios of (A) 5, (B) 10, (C) 15 are silicon chlorides, whereas simple hydrocarbons are the C-bearing gas species. These findings are consistent with previous observations.…”

“…[5][6][7][8][9] Chemical vapor deposition (CVD) and infiltration (CVI) are among the most feasible and widely studied SiC fabrication approaches because of their ability to handle complex geometry, flexible processing conditions, and the high purity, high density, and excellent crystalline morphology of the prepared SiC. [10][11][12][13][14][15][16][17][18][19][20] Methyltrichlorosilane (CH 3 SiCl 3 , MTS) is the most commonly used gas precursor for CVD and CVI of SiC [15][16][17][18][21][22][23][24] owing to its equivalent ratio of silicon (Si) to carbon (C) and the wide range of allowable deposition temperatures. Hydrogen (H 2 ) is frequently used as the carrier and diluent gas with MTS, both delivering the MTS precursor to the reactor and regulating the concentration of mixed gas precursors.…”

Progress and challenges towards additive manufacturing of SiC ceramic

“…The three-point bending strength was only about 200 MPa and the fracture toughness was as low as 3.4 MPa•m 1/2 . Baux et al [57] prepared a macroporous SiC ceramic framework by using BJ. Then, a combination process of CVD and CVI was used to obtain the final large-pored SiC ceramic component, as shown in Fig.…”

Complex geometry macroporous SiC ceramics obtained by 3D-printing, polymer impregnation and pyrolysis (PIP) and chemical vapor deposition (CVD)

“…This processing step is largely inspired by [42]. The CVD reactor consisted of a sintered silicon carbide tube, with an inner diameter of 63.5 mm.…”